Treatment of hydrocarbons



ocr. 17, 1944.

G. EGLOFF TREATMENT 0F. HYDROCARBONS Filed June 7, 1940 Mazza/41476707@ VPatented Oct-i 7, 1944 UNITED srii'rizsl vPATENT OFFICE TREATMENT F HYDROCARBONS Gustav Egloif, Chicago, Ill., assignor to Universal Oil Products Company, Chicago, Ill., a corporr tion of Delaware Application June 7, 1940, serial No. 339,291

z Claims. (01.196-52) This invention relates to the treatment of hydrocarbon oils to produce large yields of high antiknock gasoline. More specifically, it is directed to the cracking treatment of hydrocarbon oil by catalytic and thermal means where the oil and conversion products therefroml are selectively utilized in the production of large yields of said high antiknock gasoline.

In one specific embodiment thepresent invention comprises admixing a powdered cracking catalyst with a relatively heavy hydrocarbon oil which may be vaporized without substantial deing a relatively light and a relatively heavy fraccomposition, together with reiiux condensate of a similar boiling point range and formed as hereinafter described, and heatingo the admixture under adequate conditions of time, temperature and pressure to produce substantial yields of high antiknock gasoline in the presence of -a hydrogen-containing gas from the process and similarly admixing a reforming catalyst powder with a relatively light hydrocarbon oil containing also insuiiiciently converted hydrocarbons of similar boiling point range and formed as hereinafter described, heating the admixture under adequate conditions of time, temperature and pressure to produce high antiknock gasoline in the presence tion are separately subjected toselective catalytic cracking'treatment in the presence of catalyst powder whereas heavy hydrocarbon fractions such as hydrocarbon oils having a higher tendency to deposit carbonaceous material and insufiiciently converted` hydrocarbons therefrom are subjected to thermal cracking treatment, As a net result, a wide range of hydrocarbon oils are vutilized as charging stock under selective conditions suitable for producing maximum yields of high antiknock gasoline., Highly branched chain hydrocarbons are produced as a. result of the of relatively saturated gases from the process, di-

recting these reaction products to a reaction chamber together with other hydrocarbons undergoing thermal cracking treatment as hereinafter described, separating the products of the mixed reactions into a non-vaporous liquid resi'- due and vaporous products, removing the nonvaporous residue asa product of the process and fractionating the 'vaporo'us products to separate catalytic cracking treatment and the introduction of saturated gases from the process and hydrogen-containing gases into the fractions undergoing selective cracking and reforming treatment increases the degree of saturation of the products andv reduces the rate of carbon deposition -upon the catalyst, thermally andv catalytically cracked reaction products, hydrogen transfer reaction are fagasoline and gaseous hydrocarbons from insuifly ciently converted hydrocarbons, condensing and separating the insufliciently converted products into a relatively heavy fraction for thermal treatment as will be hereinafter described, also anintermediate and a light reux condensate for separately admixing withv hydrocarbon oil fractions directed to catalytic cracking treatment as hereinabove described, introducing to the process a heavy oil for thermal cracking in combination with said heavy reflux condensate and directing the products from thermal cracking treatment intov the'catalytically converted products flowing to said-reaction chamber, stabilizing the gasoline and gas from said treatments-and producing stabilized gasoline of high antiknock value, a fraction relatively rich in Cs and C4 hydrocarbons and a' hydrogen-containing gas. whichis subjected in part to further treatment with intermediate boils..

vored which also function to saturate the gasoline product. Other features of the invention will become apparent in connection with the description of the flow and specic features involved in the attached diagrammatic drawing.

The catalyst powder employed particularly in catalytic cracking reactions" may be from a naturally occurring material or may be an artificial catalyst of a m re or less porous vand refractory nature such as the type consisting essentially of siliceous and al nous'materiaL The particular catalytic material employed will depend in some measure upon the extent of the catalytic cracking of theY oil, the manner of handling the spent catalyst'and the character of the gasoline product., Untreated or acid-treated clays, kieselguhr or fullers earth in some cases with added difgcultly reducible oxides, are suitable,

likewise synthetically composited catalysts suchl as hydrated silica and hydrated alumina. concurrently or separately precipitated and prefl erably washedfree from detrimental adsorbed ing hydrocarbons as hereinbefore' described, sub-"W55 impurities. Special methods may boe employed As a result of mixing the whereby a finely divided powder of low density is obtained. Generally speaking, the primary and major component is a precipitated hydrated silica which is usually admixed with a precipitated hydrous metal oxide such as alumina, zirconia, or mixtures thereof, and present in minor proportions.

According to one general method of preparation, the hydrated silica maybe precipitated from a dilute solution of a commercial Water-glass under carefully regulated' conditions and subsequently admixed with the remaining hydrous oxide components. The hydrated silica may be admixed with the hydrous oxide components in any suitable manner, as for example, by suspending the precipitated hydrated silica in a solution of a metal salt and e precipitating the corresponding hydrous oxide in the presence of the suspended hydrated silica by the addition of a suitable alkaline precipitant. Various otherprocedures may be followed wherein these components may be co-precipitated or separately precipitated, and the components intimately'admixed whether one or more hydrous oxidesare composited with the hydrated silica. Added hydrous oxides may be simultaneously or consecutively deposited. may also be heated in solutions of metal salts and hydrous oxides deposited in the presence of hydrated silica by hydrolysis, or the precipitated hydrated silica may be admixed with a relatively concentrated solution of a metal salt to form a paste and then heated to deposit the desired metal oxides. Where alkali metal impurities such as sodium compounds have been adsorbed into the catalytic material during preparation, it may be desirable to treat the material at some state of its preparation in or'der added alumina and/or zirconia.

AWhile the above described lsilica-alumina type catalysts are particularly useful in catalytic cracking reactions, they may also be employed in the reforming reactions carried out in the present process. Other reforming catalysts may also be utilized, however, such as activated alumina supporting oxides of the'elements in the left-hand column of groups IV, V and VI of the periodic table.' In these catalysts the alumina constitutes the major component whereas the remaining components are present in minor proportions. Various other oxides have been utilized as ythe major component such as lzinc oxide, titanium oxide and various others but goodv results are obtained when utilizing activated alumina which is substantially in the gamma form. Although the activated gamma form of alumina may belused in the preparation of the catalyst;

it is alo`possible to utilize aluminum hydroxide or aluminum hydrate which maybe subsequently dehydrated and activated at a temperature of approximately 1200 F. The added oxide `is preferably an oxide of chromium which when properly prepared :is in the sesqui-oxide form.

The hydrated silica range. Heated and catalytically reformed products leaving the heating. element' 24 which may' have been more or less completely reacted in the When preparing the catalyst, a solution of chromium trioxide is usually added to the activated alumina preferably while in a ne state of division and is subsequently dried'and calcin'ed at a temperature of approximately 850-1200 F. From 5 to 35% or more of chromium sesquioxide, based on the activated alumina, is effective in for use in the reforming reactions subsequently described.

The accompanying drawing illustrates diagrammatically in conventional side elevationone specific form of apparatus which may be used to accomplish the objects of the invention.v It is not drawn to any exact; or relative scale and serves only as an villustrationof the scope of the basic features constituting thelinvention.

Referring to the drawing, a relatively heavy hydrocarbon oil which may be vapori'zed without substantial decomposition and containing a suspension of cracking catalyst powder is admitted to the process through line I and valve 2 leading to pump 3 which pumps this oil through line 4 and valve 5 into line 6 where it is admixed with insuiliciently converted hydrocarbons xhavinga similar boiling range and hydrogen-containing gas produced in the process and introduced from the absorber column by line 96 and then directed to the heating element 1. heated in furnace 8.l

ing drum. Il'wherein non-vaporized oil containing more or less spent catalyst is separated from vaporous reaction products, the non-vaporous fraction being withdrawn through line II.' regulated by valve I2 and the vaporous products flowing through line I3 and ,valve I4 into line I5 where these products are mixed with other cracked products flowing to reaction chamber IB.

Similarly, a relatively light hydrocarbon charging stock such as naphtha for example, and containing in`suspension a reforming catalyst powder, isadmitted to the process through line I'I containing valve I8 leading to pump I9 whichy pumps this oil through linel v2li containing valve 22 and into line 23 where it may be admixed with insufficiently converted products produced in the process as hereinafter described and then directed to heating element 24 heated in furnace 25. Temperatures and pressures will usually be somewhat higher than those above described for catalytic cracking and will be substantially within the same to the separating drum 28 where a non-vaporized oil containing more or less spent catalyst is separated from vaporous'products, the non-vaporous fraction being withdrawn throughline 29 reguassauts lated by valve 38 and the vaporous products owing through line 3| and valve 32 and then into line l5 leading into said reactor I6. A relatively heavy hydrocarbon oil as compared with the said `oils introduced into the process through lines c and |1 is admitted to the process through line 33 containing valve 34 leading to pump 35 which pumps this oil through line 36 and valve 31 for mixing with a heavy reflux condensate separated in fractionating column 43 as will be hereinafter described admitted through line 63 and is then directed to heating element 38 heated in furnace 39. This hydrocarbon oil is thermally cracked under thermal cracking'conditions of approximately 850-1000" F. and approximately 180 to 500 pounds per square inch pressure. The products leaving heating element 38 are directed through line I5 regulated by valve 48 into said reaction chamber I6 fo'x` admixture with said catalytically treated products undergoing 'reaction; Products from thermal and catalytic cracking are removed from reactor |6 through line 4| regulated by valve 42 and are directed to the separating chamber 43 where non-vaporous residue is separated from vaporous products. non-vaporous lresidue is removed from separating chamber 43 through line 44 regulated by valve 45 and vaporous products are removed through line 46 containing valve 41 and directed into the fractionating and separating column 48 where insumciently converted products are separated Hydrocarfrom gasoline-containing products. bons of gasoline boiling point range are removed overhead together with gaseous hydrocarbons through line 48 containing valve 58 andv iiow through condenser 5| where they are cooled and condensed.. and thence directed through line 52 containing valve 53 to receiver 54 where the gasoline product is separated from normally gaseous hydrocarbons. A portion of the gasoline product in receiver 54 is removed through line 55 containing valve 56 and directed to pump 51 whichv pumps this oil through line 58 yand. regulated byl valve 59 into the'top of-fractionating and separating column to assist in controlling the character of the overhead product. Insuiiiciently converted products in fractionating and separating column 48 are separated into a relatively heavy high boiling reflux condensate,- an intermediate boiling and a relatively light boiling reflux condensate..

Said heavy reflux condensate is withdrawn from the bottom of the column 48 through line 68 containing valve 6| leading to pump 62 which pumps this cil lthrough line 63 and valve 64 into line 36 Whereit is admixed with heavyy oil directed to the process for thermal cracking treatment as hereinabove described. Insulciently converted hydrocarbons of intermediate boiling point range are removed from column 48 through line 65 containing valve 66 leading to pump 61 which pumps this oil through line 6 containing valve 68 where it is admixed with relatively heavy oil which will not undergo substantial decomposition under vaporization introduced through line 4 and hydrogen-containing gases introdldY through line 96 whereupon the mixture undergoes catalyticcracking treatment as hereinabove described.

The

parafdnic gases admitted through line |38 which are then catalytically cracked as hereinabove described.

Unstabilized gasoline removed from receiver 54 is removed through line 2| regulated by valve 13 leading to pump 14 which pumps thisl oil l through line -15 and valve 16 into the stabilizing column 11. stabilizing column to effect partial vaporization thereof by indirect heat exchange with the heat exchanger 18 which may be suppl-led with hat from an oil at suitable temperature from the process or by steam. The stabilizer is preferably operated sothat gases rich in C3 and C4 hydrocarbons are removed fromthe stabilized gasoline,

the top temperature being controlled by passing a cooling medium through the cooling coil 19.

lThe stabilized gasoline isremoved from the bottom of stabilizing column 11 through line |32 regulated by valve |33 and gases rich in Czcand C4 hydrocarbons flow from the top of stabilizer through line 88 and valve 8| leading tothe heatingelement ||3 andthence tov the polymerizing chamber 82 for polymerizing treatment as will be subsequently described. Gaseous hydrocarbons which may be rich in C3, C4. and even C5 hydrocarbons are removed from the receiver 54 through line 83 regulated by valve 84 leading to the com- S presser 85 which compresses these gases and directs them through line 86 and valve 81 -to the absorbing column 88 where the gases rich in C3 and higher hydrocarbons are preferably removed from said gases. A hydrocarbon oil from an external source or a product of the process may be utilized as an absorber oil and admitted to the ing hydrocarbons thereby absorbing C; and higher hydrocarbons. Hydrogen-containing gases consisting largelyv of hydrogen admixed with methane' and C2 hydrocarbons are removed from the absorbing column 88 through line 9| containing valve 92 and may be removed in part from the process through line 93 regulated by valve 94 and the remainder directed to the compressor 95 which cbmpresses this gas and directs it through line 96 containing val-ve 91 into theoil being directed to heating element 1 for catalytic cracking -treatment as hereinabove described. Enriched absorber oil is removed from the bottom of column 88 through line98. and valve 99 leading to pump |88 which pumps this oil through Y line |8| and valve |82 into the stripping column Insufilciently converted hydrocarbons of relatively light boiling point range are removed from fractionating column '48 through line 69 contain-l ing valve 18 leading to pump 1| which pumps this oil through line 23 containing valve 12 where this oil is admixed with relatively light hydrocarbon oil charged to the process through line 28 and |83. Heat is supplied to the absorber oil at the bottom of stripping column |83 through heat exchanger |84 which is supplied with heat by means of heated oilv from the process or steam, and cooling at the ytop of the stripping column is carried out by means of cooling coil |85. The column is preferably operated so that gases rich in Ca and C4 hydrocarbons are removed overhead and the absorber oil removed contains C5 or higher hydroing through` line 88 as previously described.

The oil is heated in the bottom of..V

These gases are directed to the compressor which compresses and directs them through line and valve ||2 to heating element Ill and located in furnace IH where the hydrocarbons are heated under pressure to a temperature suitable for polymerization reactions and are then directed through line ||5 containing valve ||6 Vto the polymerizing chamber 82. The polymerizv ing reaction may be carried out in any desired manner, the preferred method, however, 'being in the presence of a phosphoric acid catalyst consisting essentially of orthophosphoric acid dis- /posed upon-a siliceous adsorbent. The temperatures employed when using supported phosphoric acid catalyst may be within the range of 200 to 650 F. and pressures employed may range from 100-1000 pounds or more per square inch. Polymerized products are removed from the polymerizing chamber 82 through line |I1 regulated -removed in part through line |21 regulated byl valve |28, the remainder being directed to a compresser |29 which compresses these gases and directs the compressed gas through line |30 and valve I3 into the hydrocarbon oil flowing through are directed to said reaction f vessel and commingled with hydrocarbons undergoing reaction as hereinbefore and, hereinafter described. Reduced Mid-Continent crude oil in admixture with heavy reflux condensate resulting from the fractionation of the insuillciently converted products sel. The reaction products from thermal and catalytic cracking are directed to a separating chamber from which the liquid residue is withdrawn which is a'fuel oil grade and corresponds to approximately 15% based' on the total oil charged to the process. The spent silica-alumina and alumina-chromia powders suspended in nonvaporous hydrocarbon oil from the respective steps of the process may be separately directed to flashing for other treatment whereby spent catalyst powder is separated from contained hydrocarbon oils, said separated hydrocarbon voils being further converted in the succeeding'steps described while the catalysts are regenerated by solvent and/or oxidation treatment to remove hydrocarbonaceous deposits whereupon the regenerated catalyst powders are returned to the respective steps in admixture with fresh catalyst.' Vaporous'products are directed to the v fractionating system where insufliciently conline 23 for conversion treatment in'heating element 24 ashereinabove described.

An example of one specific operationv of the process as it may be accomplished in an apparatus such as illustrated and above described is approximately as follows: A distillate fraction from Mid-Continent crude oil corresponding approximately to a heavy gas oil cut containing in admixture therewith insufllciently converted hydrocarbons of similar boiling point range produced in the process as hereinafter. described and having added thereto also aA hydrogen-containing gas produced in the process, is admixed with approximately 1% by weight of a synthetic silica-alumina catalyst powder prepared according to procedures above described. It is then heated to atemperature of approximately 900 F. at a pressure of approximately 100 pounds per square inch and is passed to a separating drum where substantially spent catalyst is removed as a suspension in a non-vaporous oilv and the vaporous products are directed into a reaction vessel and coml'niigled with other fractions undergoing cracking treatment ashereinafter described. Similarly, a distillate fraction correspondingto a heavy naphtha cut having admixed therewith insuiiiciently converted hydrocarbons of similar boiling point-range produced in the process as hereinafter described and having also added thereto paraftlnic gases remainverted products are separated and subjected to further conversion treatment as hereinabove described while the gasoline and gaseous products are removed overhead and cooled, condensed and separated. Ihe unstabilized gasoline and gases are subjected to stabilization treatment in conventional equipment whereby a stabilized gasoline is formed and two gaseous fractions, one rich in Cs and C4 hydrocarbons and the other consisting essentially of hydrogen, methane and Cz hydrocarbons. The Cs and C4 hydrocarbons are subjected to polymerizing treatment in the presence of a solid phosphoricacid catalyst at a temperature of approximatelyl 475 F. using a pressure of approximately 400 pounds per square inch. The polymer gasoline therefrom is admixed with the gasoline product from the process while the residual parafiinic gases are admixed with the relatively light hydrocarbons directed to conversion treatment in the presence of aluminachromia catalyst powder as hereinabove described. Saidhydrogen-containing gas separated from Ca 'and C4 hydrocarbons is admixed in part with the hydrocarbons substantially of gas oil boiling point range admitted to the process in admixture with insufficiently converted hydrocarbonsand containing silica-alumina catalyst powder? as hereinabove described. This operation will'yield approximately 76% of 76 octane ing after polymerization treatment of C: and C4 hydrocarbons resulting from the process, is admixed with approximately 2% by weight of an alumina-chromia powder prepared by depositing approximately 8% chromia upon activated alumina. It is then heated at a temperature of approximately 975 F. under a pressure of approximately 500 pounds perY square inch and directed into a separating drumwherein a small amountv of non-vaporous residue'containing relatively spent catalyst powder is separated and withdrawn while the vaporous reaction products number vgasoline based on the total oil charged to the process, non-vaporous residue being separated in the amount noted while the balance is attributed mainly to normally gaseous products', only a relatively small percentage appearing as hydrocarbonaceous deposits upon the catalyst powders.

Ilclaim as my invention:

1. A process for the conversion of hydrocarbon oil which comprises catalytically reforming a relatively light oil, catalytically cracking a heavier oil and thermally cracking a residual oil, combining resultant conversion products, separating residue from vapors, fractionating said vapors to separate and condense light, intermediate and mally gaseous hydrocarbons, subjecting said heavy reux condensate from the fractionated vapors, supplyingkaid light refux condensate to the catalytic reforming step, supplying said intermediate reflux condensate to the catalytic .5

cracking step, supplying said heavy reux con- 4 densate to the thermal cracln'ng step, cooling and' heavy gas fraction to polymerization, supplying unpolymerized gases vto the catalytic reforming step and at least a portion of said light gas fraction to the catalytic cracking step.

2.- The process of claim 1 further characterized and catalytic cracking in the presence of a pow- 10 dered cracking catalyst.

GUSTAV EGIDFF. 

